Diabetes mellitus is a major public health problem. In the United States, there are over 10 million patients with diabetes. Diabetes is a syndrome that is caused by a relative or an absolute lack of insulin. Clinically, it is characterized by symptomatic glucose intolerance as well as alterations in lipid and protein metabolism. The maintenance of normal blood sugar levels is achieved by the actions of several hormones, most notably insulin, but also glucagon, epinephrine, corticosteroids, and growth hormone. On the other hand, hyperglycemia is exemplified by higher than normal concentrations of glucose in the blood. The pancreas produces insulin which is released in response to increased blood glucose concentrations. Insulin works to lower the blood sugar levels by stimulating the uptake of glucose by cells. Glucose is used in cellular metabolism to produce energy, or is converted to glycogen for storage in the liver and muscles, or is used in the production of triglycerides and fats.
Crawford (J Am Board Fam Med, 22: 507-512, 2009) reports the effectiveness of cinnamon for lowering hemoglobin A1C in patients with type 2 diabetes.
Khan et al (Diabetes Care, 26: 3215-3218, 2003) report that intake of 1, 3, or 6 g of cinnamon per day reduces serum glucose, triglyceride, LDL cholesterol, and total cholesterol in people with type 2 diabetes.
Solomon et al (Diabetes Obes Metab, 9:895-901, 2007) report that cinnamon ingestion reduced total plasma glucose responses to oral glucose ingestion, as well as improving insulin sensitivity as assessed by insulin sensitivity index.
Water extracts of cinnamon exhibit an insulin potentiating activity, i.e. they increase apparent insulin activity as measured by increased glucose uptake by cells (U.S. Pat. No. 6,200,569).
Mang et al (European J. Clin. Invest. 36:340-344, 2006) report that diabetes mellitus type 2 patients treated with 3 g of cinnamon water extract powder per day for 4 months decreased fasting plasma glucose level, in comparison with placebo-treated patients.
Traditional Chinese medicines such as Radix Astragali, Radix Rehmanniae, and Rhizoma Coptidis can lower blood glucose and control inflammation (Xie et al, Diabetes Obes Metab, 2011, 13:289-301). The water extract of the fruit of Momordica charantia L. was reported to reduce the blood glucose of KK-AY mice 3 weeks after oral administration (Miura et al., J. Nutr. Sci. Vitaminol, 2001, 47: 340-344). The exact of Begonia fimbristipula was reported to improve kidney filtration function and improve the clinical symptoms of diabetic nephropathy rats (Wang et al., Chinese J. Biochemical Pharmaceutics, 2012, 33: 272-277).
Kim et al (Diabet Med., 30:1075-9, 2013) analyzed the clinical and laboratory data of over 17,000 Korean adults who underwent routine medical examinations with a median interval of 3.5 years to study relative contributions of insulin resistance and β-cell dysfunction to the development of type 2 diabetes in over 17,000 Koreans. Kim et al report that among the participants who developed diabetes, 29% demonstrated predominant β-cell dysfunction dysfunction and 51% had predominant insulin resistance.
Song et al (Diabetes care, 30:1747-52, 2007) report that high homeostasis model assessment (HOMA) of insulin resistance and low HOMA of β-cell function were independently and consistently associated with an increased diabetes risk in a multiethnic cohort of U.S. postmenopausal women.